8,650 research outputs found
Neogene paleoceanography of the eastern equatorial Pacific based on the radiolarian record of IODP drill sites off Costa Rica
The Integrated Ocean Drilling Program (IODP) Expedition 344 drilled cores following a transect across the convergent margin off Costa Rica. Two of the five sites (U1381 and U1414) are the subject of the present study. Major radiolarian faunal breaks and characteristic species groups were defined with the aid of cluster analysis, nodal analysis, and discriminant analysis of principal components. A middle-late Miocene to Pleistocene age (radiolarian zones RN5 to RN16) was determined for the sites, which agrees with the nannofossil zonations and 40Ar/39Ar and tephra layers. Considering the northward movement of the Cocos plate (∼7.3 cm/yr), and a paleolatitude calculator, it is assumed that during the Miocene the two sites were located ∼1000 km to the southwest of their current position, slightly south of the equator. The radiolarian faunas retrieved were thus seemingly formed under the influence of different oceanic currents and sources of nutrients. Changes in the radiolarian assemblages at Site U1414 point at dissimilar environmental settings associated with the colder South Equatorial Current and the warmer Equatorial Countercurrent, as well as to coastal upwelling. These differences are best reflected by changes in the abundance of the morphotype Spongurus spp., with noticeably higher values during the Miocene, than in the Pliocene and the Pleistocene. Because Spongurus spp. is generally associated with cooler waters, these abundance variations (as well as those of several other species) suggest that during the Miocene the area had a stronger influence of colder waters than during younger periods. During the Pliocene and the lowermost Pleistocene, biogenic remains are scarce, presumably due to the terrigenous input, which could have diluted and affected the preservation of pelagic fossils, as well as to the displacement of the site to warmer waters. A typically tropical fauna characterized the Pleistocene, yet with widespread presence of colder water species, most probably indicative of the influence of coastal upwelling processes.Fil: Sandoval, María I.. Universidad de Costa Rica; Costa Rica. Universite de Lausanne; SuizaFil: Boltovskoy, Demetrio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Baxter, Alan T.. University of New England; Australia. McGill University; CanadáFil: Baumgartner, Peter O.. Universite de Lausanne; Suiz
Consumers Behavior with Information-Processing Capacity Constraints
This study analyzes the consumer behavior to highlight the intervening processes and factors in the decision-making process, taking as a reference the act of purchase. The contribution of this paper is to approach representative concepts for analytical purposes on decision making processes and advance in the analysis of the limited capacity of the consumer. We show decisions and preferences of the same purchase are not constant over the time, instead, are outcome of a complex process, affected by circumstances and environment that takes place in a given time. Focus on the reasoning ability underlies of purchase decision, a flow diagram was designed to represent a type of limited information processing model. Then, according to the theoretical framework of Rubinstein (1998) We introduce a model of agent with limited capacity in the of processing of information. The model has a variant on the structure of consumer information ‘brand effect’ and it supposes loss aversion "effect minimum satisfaction". Keywords: Consumer Behavior, bounded rationality, the information processing theory, making decision, preference of the consumer
Enhancement of photoacoustic detection of inhomogeneities in polymers
We report a series of experiments on laser pulsed photoacoustic excitationin
turbid polymer samples addressed to evaluate the sound speed in the samples and
the presence of inhomogeneities in the bulk. We describe a system which allows
the direct measurement of the speed of the detected waves by engraving the
surface of the piece under study with a fiduciary pattern of black lines. We
also describe how this pattern helps to enhance the sensitivity for the
detection of an inhomogeneity in the bulk. These two facts are useful for
studies in soft matter systems including, perhaps, biological samples. We have
performed an experimental analysis on Grilon(R) samples in different situations
and we show the limitations of the method.Comment: 8 pages, 7 figure
BlazePose-Based Action Recognition with Feature Selection Using Stochastic Fractal Search Guided Whale Optimization
The BlazePose, which models human body skeletons as spatiotemporal graphs, has achieved fantastic performance in skeleton-based action identification. A Spatial-Temporal Graph Convolutional Network can then be used to forecast the actions. This architecture performance can be improved by simply replacing the skeleton input data with a different set of joints that provide more information about the activity of interest. On the other hand, existing approaches require the user to manually set the graph's topology and then fix it across all input layers and samples. This research shows how to use Stochastic Fractal Search - Guided Whale Optimization Algorithm in conjunction with the BlazePose skeletal data to construct a novel implementation of this topology for action recognition. We utilized the NTU-RGB+D and the Kinetics datasets as benchmarks in our experiments
Sensitivity Analysis and Quantification of the Role of Governing Transport Mechanisms and Parameters in a Gas Flow Model for Low-Permeability Porous Media
Recent models represent gas (methane) migration in low-permeability media as a weighted sum of various contributions, each associated with a given flow regime. These models typically embed numerous chemical/physical parameters that cannot be easily and unambiguously evaluated via experimental investigations. In this context, modern sensitivity analysis techniques enable us to diagnose the behavior of a given model through the quantification of the importance and role of model input uncertainties with respect to a target model output. Here, we rely on two global sensitivity analysis approaches and metrics (i.e., variance-based Sobol’ indices and moment-based AMA indices) to assess the behavior of a recent interpretive model that conceptualizes gas migration as the sum of a surface diffusion mechanism and two weighted bulk flow components. We quantitatively investigate the impact of (i) each uncertain model parameter and (ii) the type of their associated probability distribution on the evaluation of methane flow. We then derive the structure of an effective diffusion coefficient embedding all complex mechanisms of the model considered and allowing quantification of the relative contribution of each flow mechanism to the overall gas flow
Ramon (\u3ci\u3eBrosimun alicastrum\u3c/i\u3e) Foliage as Supplement for Lactating Dual Purpose Cows
The objective of the present study was to asses the value of ramón (Brosimun alicastrum) foliage as a N-source in replacement of soybean-N in lactating dual purpose cows (Bos indicus x B. taurus). Four lactating cows were used in a latin rectangle design. Ramón was included to replace 0, 33, 66 and 100 % of the soybean-N contained in the supplement. Basal diet was fresh “Taiwán” a cultivar of Elephant grass (Pennisetum purpureum) fed ad libitum. Basal and total dry matter intake, digestibility (total fecal collection), saleable and calf suckled milk yields, and milk composition (fat, protein and lactose) were measured over 15 d periods. Ramon increased the yield of milk constituents (P\u3c 0.05) over those obtained with Taiwán-grass alone, but was inferior (P\u3c 0.05) when soybean was the N source. Total milk yield was reduced 18% in Ramón supplemented cows compared with those supplemented with soybean. Digestibility of dry matter, organic matter and fiber was reduced by Ramón inclusion probably due to its higher fiber and ash content as compared with soybean meal. It was concluded that, although animal performance was not achieved as with soybean meal, supplementing with Ramón is a better strategy than relying on grass alone
Enfrentamiento terapéutico del trastorno por déficit atencional en una población infantil escolar perteneciente a la Región Metropolitana de Chile
Indexación: ScieloAn evaluation was made of a retrospective evolution presented by the patients from to 14 years and 11 month old (average 9,2 years old), with a diagnostic of attentional hyperactive disorder (AHD), treated with metilfenidate in Huechuraba during the year 2007. A revision of every clinic history showed the principal results: a high positive response (higher than the 76% of the measured parameters). The evaluated parameters were, academic response, self report of subjective opinion from the patient, opinion from the tutor of the child in relationships with his/her conduct at home and teacher's evaluations of the child conduct at school. No differences were found between the evolution of the clinic parameters, in children with and without comorbilities. It was found a 52, 7% of comorbility. Specific learning disease, adaptative disorder, anxious disorder, and depression were more frequent diagnoses. This study concludes that the high percent of success in the treatment of the student group is similar to the one found in literature. The presence of comorbility won't cause to down of the treatment efficiency. This is conditioned by the presence of psychosocial factors like maternal psychopathology and familiar violence.Se realizó una evaluación restrospectiva de la evolución presentada por los pacientes desde 6 a 14 años 11 meses de edad (edad media de 9,2 años) con diagnóstico de Trastorno por déficit atencional (TDA) bajo tratamiento con metilfenidato en la comuna de Huechuraba durante el año 2007. Se hizo la revisión y el análisis de cada ficha clínica, encontrándose como principales resultados el alto porcentaje de mejoría, igual o mayor al 76% de los parámetros medidos, consistentes en evolución del rendimiento académico; autoreporte de sensación subjetiva del niño; reporte del cuidador principal en relación a la conducta del niño (a) en el hogar y evaluación del profesor en cuanto su conducta en el colegio. No se encontraron diferencias entre la evolución de los parámetros clínicos entre los niños con comorbilidad y sin comorbilidad, se encontró un 52,7% de esta, siendo los diagnósticos más frecuentes Trastorno específico del aprendizaje, trastorno adaptativo, trastorno ansioso y del ánimo. Se concluye que el alto porcentaje de éxito del tratamiento en el grupo estudiado es similar al encontrado en la literatura; que la presencia de comorbilidad no condiciona la disminución de la eficiencia del tratamiento y que esta es condicionada por presencia de factores psicosociales como psicopatología materna y violencia intrafamiliar.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-92272009000100005&nrm=is
Differences in Relationship and Sexual Satisfaction and Social Support Between Only Lesbian, Mostly Lesbian, and Bisexual Women
Research suggests relationship and sexual satisfaction and social support are correlated with components of well-being such as anxiety, depression, and physical health. Differences in relationship and sexual satisfaction and social support have been identified between sexual minority women (SMW; i.e., lesbian and bisexual) and heterosexual women. However, classifying SMW into a single group may mask important differences. Further research is needed to better understand the differences in relationship and sexual satisfaction and social support between subgroups of SMW. Thus, the purpose of the present study was to examine differences in these constructs between women who identify as only lesbian, mostly lesbian, and bisexual. Participants were 427 partnered sexual minority women (Mage = 24.66; 84.8% White; 46.8% only lesbian; 34.2% mostly lesbian; 19% bisexual) recruited from social media to complete an online survey consisting of measures of relationship, health, and related factors as part of a larger study. A one-way ANOVA revealed statistically significant differences between only lesbian, mostly lesbian, and bisexual women in relationship satisfaction (p=.021), sexual satisfaction (p=.049), and social support (p=.034). Post-hoc pairwise comparisons revealed women who identified as only lesbian reported better relationship satisfaction (p=.007), sexual satisfaction (p=.015), and social support (p=.010) than women who identified as mostly lesbian. There were no differences between bisexual women and women who identified as either only lesbian or mostly lesbian. These findings identified important differences between subgroups of SMW, with women who identify as mostly lesbian reporting the lowest relationship and sexual satisfaction and social support. This study provides further evidence that collapsing across identities within the broad category of SMW may mask meaningful subgroup differences. Additional research is needed to further explore disparities in well-being among subsections of SMW. Findings may help identify important protective factors for mental and physical health and well-being specific to SMW of different identities.https://digitalcommons.odu.edu/gradposters2023_sciences/1007/thumbnail.jp
Nitrogen form and root division modifies the nutrimental and biomolecules concentration in blueberry (Vaccinium corymbosum L.)
Blueberry (Vaccinium corymbosum L.) continues to gain importance in the international market due to its effects on the prevention of human diseases. This leads to the need to optimize the production and quality of the fruit. The present research evaluated the effect of NO3- and NH4+, using the split roots technique, in the nutritional status, photosynthetic pigments and total sugars in blueberry leaves. A completely random experiment was established with six greenhouse treatments: three under homogeneous root conduction (HR) and three with split roots (SR). The concentration of N, P, K, Ca, Mg, S, Fe, Cu, Zn, Mn, B and Na, chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoids (Car) and total sugars were evaluated in the leaves. The exclusive supply of NH4+ led to the largest accumulation of N, P, Mg, S, Cu, Mn and B, compared to plants treated with NO3-. The Chla and total sugars were higher with NH4+ compared to NO3- nutrition. The supply of N separately (SR) had no positive effects on the evaluated variables, however, the SR with half of N, in the form of NH4+, compared to the non-SR with full application of N, has no differences in N-leaf concentration, which implies a higher use in the uptake or accumulation of this macro element in plant. V. corymbosum L. with split root and half of N in the form of NH4+, doubled the N use efficiency, as it matches in yield the complete supply treatment of N-NH4+ without root division
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